rock

 big

pebble

 not as big

sand

0.06 – 2mm = 60,000 - 2,000,000 nm

dirt

 smaller

pollen

10 – 100 um - = 10,000 - 100,000 nm

milk

 100 nm (casein particle)-1000 nm (fat drop)

Human cell

10,000 nm

colloid

1-1000 nm

bacterium

1000 nm

220 nm (0.22 um) filter

virus

50 nm; influenza 120 nm diam

protein

 15 nm

water

 0.3 nm